1. Field of the Invention
This invention relates to novel penicillins and cephalosporins and to a process for producing the same.
The compounds of the present invention have various characteristics including antibacterial activity of a broad spectrum against Gram-positive and Gram-negative bacteria, and effective antibacterial activity particularly against Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus species. Furthermore, the compounds of the present invention possess high resistance of .beta.-lactamase produced from bacteria, and effective antibacterial activity even against clinical isolates of bacteria which are significant at present from a clinical standpoint. Accordingly, the compounds of the present invention are quite effective as therapeutic drugs for human and animal infections diseases derived from the above-mentioned pathogenic microorganisms.
2. Description of the Prior Art
It has heretofore been known that 6-acylamino penicillanic acids and 7-acylaminocephalosporanic acids having an amino group at the .alpha.-position of the acyl group show strong antibacterial activity not only against Gram-positive bacteria but also against Gram-negative bacteria. However, such known compounds suffer from the disadvantage that they show substantially no effective antibacterial activity against not only Pseudomonas aeruginosa, Klebsiella pneumonias and Proteus species, which are known to cause clinically serious infectious diseases, but also resistant bacteria which are frequently isolated at present fom many clinical hospitals. Moreover, they tend to be hydrolyzed with .beta.-lactamase produced from many drug-resistant bacteria.